The architecture of receivers in wireless communications is diverse for different applications and requirements. The receiver is a vital component in a wireless communication system. It is responsible for receiving and demodulating the transmitted signal and converting it into a digital signal for subsequent processing. The design of the receiver involves signal processing, radio frequency circuits, digital processing and other aspects. Different architectures will affect the performance, complexity and power consumption of the receiver. This article will introduce several common wireless communication receiver architectures, including superheterodyne receivers, direct conversion receivers, mixed-signal receivers, and software-defined radio (SDR) receivers.
- Superheterodyne receiver
A superheterodyne receiver is a common receiver architecture also known as a superheterodyne transceiver. In a superheterodyne receiver, the received RF signal is first amplified and filtered by the RF front-end, and then converted to the intermediate frequency (IF) range by a mixer. The signal then undergoes a series of intermediate frequency amplification, filtering and demodulation processes, and is finally converted into a baseband signal. The advantage of this architecture is that it is simple and mature, and is suitable for many wireless communication standards, such as frequency modulation (FM), amplitude modulation (AM), etc.
- Direct conversion receiver
Direct conversion receivers (also called zero-IF receivers) are another common receiver architecture. In a direct-conversion receiver, the received RF signal is directly converted to baseband, eliminating the need for IF processing. This architecture simplifies receiver design, reduces the number of zero-IF filters and IF amplifiers, and reduces power consumption and complexity. However, direct conversion receivers also face some challenges, such as local oscillator leakage and DC offset.
- Mixed signal receiver
Mixed-signal receivers combine the advantages of analog and digital processing to create a flexible and high-performance receiver architecture. In a mixed-signal receiver, the RF signal is first processed by an analog front-end and then converted into a digital signal by an analog-to-digital converter (ADC). The digital signal is demodulated and signal processed by a digital signal processor (DSP), and finally a digital baseband signal is output. Mixed-signal receivers are suitable for complex communication standards and signal processing needs, and have high flexibility and programmability.
- Software Defined Radio (SDR) Receiver
Software-defined radio (SDR) receiver is a flexible receiver architecture based on software definition. In an SDR receiver, the RF signal is directly converted into a digital signal after being processed by the RF front-end, and then demodulated and processed through a software-defined signal processing algorithm. SDR receivers are extremely flexible and programmable and can implement different communication standards and functions through software updates. SDR receivers are suitable for applications that require frequent updates and customization, such as radio communication research and military communication systems.
in conclusion
Different wireless communication receiver architectures have their own advantages and disadvantages and are suitable for different applications and needs. Superheterodyne receivers are simple and easy to implement and are suitable for general communication standards; direct conversion receivers reduce the complexity and power consumption of the IF link; mixed-signal receivers combine the advantages of analog and digital processing and are suitable for complex communication systems; and SDR receivers are extremely flexible and programmable, and are suitable for application scenarios that require customization and updates. With the continuous development of communication technology, the architecture of wireless communication receivers will continue to evolve to meet increasingly complex communication needs.